1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Harmonic curves

  1. Sep 13, 2004 #1
    Not sure if it's called "curves" in English, but what I am refering to is graphs that repeat over a given time.
    f(x) = sin(x)

    The problem I am having is understanding the following:
    f(x) = sin(x)
    g(x) = cos(x)

    Find f(x) - g(x) by A(cos(x - x0)).
    Which gives:
    A(cos(x - x0)) = A(cos(x0))cos(x) + A(sin(x0))sin(x)
    A(cos(x0)) = 1
    A(sin(x0)) = -1

    A = sqrt(1^2 + (-1)^2) = 1

    Finding x0:
    tan wx0 = 1/(-1)
    1*x0 = arctan(-1)
    x0 = -0.79

    Here I'm pretty much lost. I've probably done some mistakes along the way as well :(
    What is -0.79? x0 is supposed to be the 'top' of the curve right?
    ie to find every top, you would have something like:
    x0 +/- |n|*2PI

    Where n is a whole number(1..inf) and 2PI would be the period of each "curve".

    Could someone explain this to me, I'm trying to learn this by just reading a book and I'm having a hard time.
  2. jcsd
  3. Sep 13, 2004 #2
    sqrt(2) is sqrt(2), not 1 :rolleyes:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Harmonic curves
  1. Curves and torsion (Replies: 5)

  2. Algebraic Curves (Replies: 1)

  3. Originary curves (Replies: 5)

  4. Rectifying curve (Replies: 1)